Ultrasonic loudspeaker does not produce ordinary, audible sound waves with a single, moving, electromagnetic coil and cone. Instead, it generates ultrasound (high-frequency sound waves) with pitches too high to hear for humans. The ultrasonic loudspeaker can direct sound like a spotlight to a precise position where only certain people can hear it. When an audience is not static in one single place, he cannot perceive an ultrasound sound wave from the ultrasonic loudspeaker at any time.